Detoxified cottonseed oil foots



United States Patent DETOXIFIED COTTONSEED OIL FOOTS Frank C. Pack and Leo A. Goldblatt, New Orleans, La., assignors to the United States of America as represented by the Secretary of Agriculture No Drawing. Application May 27, 1955, Serial No. 511,814

2 Claims. (Cl. 99-2) (Granted under Title 35, U. S. Code (1952), see. 266) A nonexclusive, irrevocable, royalty-free license in the invention herein described, for all governmental purposes, throughout the world, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to cottonseed oil foots, and to oilseed meal compositions adapted for use as animal feedstuffs. More particularly, the invention provides oilseed meal compositions having improved dusting and pelleting properties due to the incorporation of non-toxic cottonseed oil foots; and provides a commercially feasible process of detoxifying the gossypol present in the typical cottonseed oil foots.

Cottonseed oil foots or soapstocks are the mixtures of soap, entrained vegetable oil and aqueous liquid which are removed from crude cottonseed oils in the course of an alkaline refining of the oil. Raw foots are the semisolid untreated mixtures, in the form in which they are produced. Raw foots contain about 35 to 50% by weight of vegetable oil fatty acids, in the form of their alkali metal salts, and about 50% by weight of water. lated foots are the black oily liquids produced by treating raw foots with a mineral acid, to release the fatty acids, then isolating the resulting organic phase consisting essentially of fatty acids and neutral oil. Acidulated foots con tain from about 85 to 95% fatty acids.

Cottonseeds usually contain from about /2 to 1 /2 of gossypol and related pigments which are somewhat toxic to non-ruminant animals. Although the seeds are often treated to detoxify the gossypol during the oil extraction, some gossypol is usually carried along with the oil. Cottonseed oil foots usually contain appreciable proportions of free gossypol. The cottonseed oil foots have very little commercial value and usually represent almost a total loss to the oil millers.

A primary object of the present invention is to provide a process of treating cottonseed oil foots, to detoxify any free gossypol they may contain, and to convert them to non-toxic cottonseed oil foots produced at substantially the same cost the untreated foots are produced. A further object of the present invention is to provide oilseed meal compositions which are adapted for use as animal feedstnifs and have improved properties, such as dusting and pelleting properties, imparted by the incorporation of the vegetable oilseed components contained in cottonseed oil foots that have been freed of any toxic gossypol or related pigments.

The gossypol contained in cottonseed oil foots is uniquely resistant toward the detoxification procedures that are capable of detoxifying the gossypol contained in cottonseed meats and/or meals. For example, heating a moist cottonseed meal at about 100 C. for a few hours will detoxify the gossypol it contains. However, the gossypol contained in cottonseed oil foots stubbornly resists such a treatment, even when the treatment is supplemented by the incorporation of iron salts and/or by air blowing and is prolonged for many hours.

However, we have discovered that, although the gossypol content of cottonseed oil foots ranges from minute traces to as much as 4%, and although analyzing the foots to determine their gossypol content and the treating conditions required for each batch would be unfeasibly expensive; non-toxic cottonseed oil foots can economically be produced, by subjecting all of the foots to a short, severe heating under pressure.

in general, in accordance with this invention, cottonseed oil foots are converted to non-toxic cottonseed oil foots containing less than about 0.02% free gossypol by heating cottonseed oil foots in a closed vessel to a temperature of from about 210 C. to 220 C. for from about 1 to 3 minutes. The invention makes it possible to produce vegetable oilseed meal compositions having improved dusting and pelleting properties. These compositions consist essentially of a vegetable oilseed meal having an oil content of from about 0.5 to 3.0 mixed with from about 1 to 10 parts per parts of meal of cottonseed foots that contain less than about 0.02% free gossypol.

The detoxified cottonseed oil foots employed can be those obtained by any of the conventional procedures for the alkaline refining of cottonseed oil. They can be employed in their raw or acidulated state. In general, the employment of raw foots is preferred. Where acidulated detoxified foots are desired, the foots are preferably de toxified in the raw state and then acidulated. The detoxified raw foots can be acidulated by means of the usual procedures and apparatus for acidulating row foots.

The foots can be heated by a continuous or batchwise procedure employing any apparatus capable of withstanding the pressure developed by heating an aqueous liquid at the specified temperature. The use of continuous procedures employing a stainless steel apparatus, such as a tubular heater, the inlet and outlet which is closed by a moving plug of the material being heated, is preferred.

In the production of the oilseed meal composition, any of the oilseed meals adapted for use as animal feedstuiis can be used. The meal can be one from which the oil has been removed by means of pressing and/0r solvent extraction. Suitable meals include cottonseed, soybean, peanut, and the like meals. The non-toxic cottonseed oil foots can be mixed wth the meals by means of the usual procedures and apparatus for mixing materials. The use of detoxified cottonseed oil foots in proportions of from about 1 to 10 parts by weight of foots per 100 parts of meal, is preferred.

The following example is illustrative of the details of at least one method of practicing the invention.

Example Samples of cottonseed oil foots obtained by a conventional soda ash refining of crude cottonseed oil were heated in closed vessels for the indicated times at the indicated temperatures. The eflfects of the treatment upon the gossypol content of the foots is summaried in the following table.

'1. A process of converting cottonseed oil foots to detoxified cottonseed oil foots containing less than about 0.02% of free gossypol, comprising, heating cottonseed 3 oil foots in a closed vessel to a temperature of from about 210 to 220 C. for from about 1 to 3 minutes.

2. A vegetable oilseed meal composition consisting essentially of a vegetable oilseed meal having an oil content of from about 0.5 to 3% mixed with from about 1 to 10 parts per 100 parts of meal of detoxified cottonseed 4 oil foots containing less than about 0.02% of free gossypol produced by heating cottonseed oil foots in a closed vessel to a temperature of from about 210 to 220 C. for from about 1 to 3 minutes.

No references cited. 

1. A PROCESS OF CONVERTING COTTONSEED OIL FOOTS TO DETOXIFIED COTTONSEED OIL FOOTS CONTAINING LESS THAN ABOUT 0.02% OF FREE GOSSYPOL, COMPRISING, HEATING COTTONSEED OIL FOOTS IN A CLOSED VESSEL TO A TEMPERATURE OF FROM ABOUT 210* TO 220* C. FOR FROM ABOUT 1 TO 3 MINUTES. 